Self cleaning water spray nozzles and valve assemblies have been employed for use particularly in humidification systems and humidifiers as evidenced by U.S. Pat. No. 2,825,602, dated Mar. 4, 1958, wherein a stem is connected at one end to a diaphragm and a thin needle or wire is connected to the opposite end of the stem and extends through the nozzle aperture to prevent the build-up of minerals therein. A valve head is mounted on the intermediate portion of the stem and adapted to engage a valve seat positioned in the nozzle, whereby the diaphragm actuates the stem and associated valve to control the water flowing axially through the nozzle.
Water spray nozzles having solenoid actuated valve assemblies have also been employed, as disclosed in U.S. Pat. No. 3,565,052, dated Feb. 23, 1971, wherein a valve is disposed between a nozzle and a solenoid, whereby the valve is actuated by the solenoid to control the flow of water through the nozzle.